<template>
    <div class="home-page">
    <div class="banner">
        <div class="container">
            <h1 class="logo-font">conduit</h1>
            <p>A place to share your knowledge.</p>
        </div>
    </div>

    <div class="container page">
      <div class="row">

        <div class="col-md-9">
          <div class="feed-toggle">
            <ul class="nav nav-pills outline-active">
              <li v-if="user" class="nav-item">
                <nuxt-link
                    class="nav-link"
                    :class="{
                        active: tab === 'your_feed'
                    }"
                    exact
                    :to="{
                        name: 'home', query: {
                            tab: 'your_feed'
                        }
                    }">Your Feed</nuxt-link>
              </li>
              <li class="nav-item">
                  <nuxt-link
                      class="nav-link"
                      :class="{
                        active: tab === 'global_feed'
                  }"
                      exact
                      :to="{
                        name: 'home', query: {
                            tab: 'global_feed'
                        }
                    }">Global Feed</nuxt-link>
              </li>
                <li v-if="tag" class="nav-item">
                    <nuxt-link
                        class="nav-link"
                        :class="{
                        active: tab === 'tag'
                  }"
                        exact
                        :to="{
                        name: 'home', query: {
                            tab: 'tag',
                            tag: tag
                        }
                    }">#{{ tag }}</nuxt-link>
                </li>
            </ul>
          </div>

          <div
              class="article-preview"
              v-for="article in articles"
              :key="article.slug">
            <div class="article-meta">
              <nuxt-link :to="{
                name: 'profile',
                params: {
                    username: article.author.username
                }
              }"><img :src="article.author.image" /></nuxt-link>
              <div class="info">
                  <nuxt-link class="author" :to="{
                name: 'profile',
                params: {
                    username: article.author.username
                }
              }">{{article.author.username}}</nuxt-link>
                <span class="date">{{article.createdAt | date('MMM DD, YYYY')}}</span>
              </div>
              <button class="btn btn-outline-primary btn-sm pull-xs-right" :class="{active: article.favorited}"
              @click="onFavorite(article)" :disabled="article.favoriteDisabled">
                <i class="ion-heart"></i> {{ article.favoritesCount }}
              </button>
            </div>
            <nuxt-link :to="{
                name: 'article',
                params: {
                    slug: article.slug
                }
            }" class="preview-link">
              <h1>{{article.title}}</h1>
              <p>{{article.description}}</p>
              <span>Read more...</span>
            </nuxt-link>
          </div>

            <!-- 分页列表 -->
            <nav>
                <ul class="pagination">
                    <li class="page-item" :class="{active: item === page}" v-for="item in totalPage" :key="item">
                        <nuxt-link class="page-link" :to="{
                            name: 'home',
                            query: {
                                page: item,
                                tag: $route.query.tag,
                                tab: tab
                            }
                        }">{{item}}</nuxt-link>
                    </li>
                </ul>
            </nav>
            <!-- /分页列表 -->

        </div>

        <div class="col-md-3">
          <div class="sidebar">
            <p>Popular Tags</p>

            <div class="tag-list">
              <nuxt-link :to="{
                  name: 'home',
                  query: {
                      tab: 'tag',
                      tag: item
                  }
              }" class="tag-pill tag-default"
              v-for="item in tags" :key="item">{{item}}</nuxt-link>
            </div>
          </div>
        </div>

      </div>
    </div>

  </div>
</template>

<script>
import {getArticles, getFeedArticles,
  addFavorite, deleteFavorite} from "@/api/article";
import {getTags} from "@/api/tag";
import {mapState} from 'vuex'

export default {
    name: "HomeIndex",
    async asyncData({ query, store }) {
        const page = Number.parseInt(query.page || 1)
        const limit = 20
        const { tag } = query
        const tab = query.tab || 'global_feed'
        const loadArticles = store.state.user && tab === 'your_feed'
            ? getFeedArticles
            : getArticles
        const [ articleRes, tagRes ] = await Promise.all([
            loadArticles({
                limit,
                offset: (page - 1) * limit,
                tag
            }),
            getTags()
        ])

        const { articles, articlesCount } = articleRes.data;
        const {tags} = tagRes.data;

        articles.forEach(article=>article.favoriteDisabled = false)

        return {
            articles, articlesCount, tags,
            limit, page, tag, tab: query.tab || 'global_feed'
        }
    },
    watchQuery: ['page', 'tag', 'tab'],
    computed: {
        ...mapState(['user']),
        totalPage() {
            return Math.ceil(this.articlesCount / this.limit)
        }
    },
  methods: {
      async onFavorite (article) {
        article.favoriteDisabled = true;
        if (article.favorited) {
          //取消点赞
          await deleteFavorite(article.slug)
          article.favorited = false;
          article.favoritesCount -= 1;
        } else {
          //添加点赞
          await addFavorite(article.slug)
          article.favorited = true;
          article.favoritesCount += 1;
        }
        article.favoriteDisabled = false;
      }
  }
}
</script>

<style scoped>

</style>